Why does your 742 carbine jam?

Answer 1

The 742 carbine is a short barrel version of the 742 rifle. The gas port is in the same location near the breach. The only problems I have seen with this model is improper cleaning and shooting light bullets. Mine would jam every time with accelerators and a lot with hand-loads under 140 grains when velocities were topped out. It seems the carbine barrel is too short to allow proper gas expansion to cycle the action before the pressure drop when the bullet exits the barrel. These same loads did fine in the rifle or when loaded slower. If shooting 165 grains or higher in factory loads or equivalent hand-loads and proper cleaning is observed then have a gunsmith who works on gas operated rifles to check out the gas system and bolt lockup.